In this request for renewal of Grant No. 5 R01 DE01919 our objectives extend and develop those of the previous grant. With the aid of the earlier grant a number of biophysical techniques were developed and made available in this laboratory for studying the microstructure and composition of teeth and bones. The value of these techniques was explored through typical applications to fossil and fresh material. Through the renewed grant we would propose to extend these applications and conclude that phase of the study which has dealt with the proteinaceous residues that can be isolated from a wide range of animal fossils.